Surface improver for reinforced composite compositions

ABSTRACT

The invention is a composition comprising a blend of two or more epoxide containing compositions selected from epoxidized vegetable oils, epoxidized alkyl esters or cycloaliphatic epoxides. In another embodiment, the invention is a blend of one or more epoxidized vegetable oils, epoxidized alkyl esters, or cycloaliphatic epoxides with one or more aromatic epoxides or epoxy functionalized polyoxyalkylene polyols.

This application is a divisional application of U.S. patent applicationSer. No. 12/288,656, filed Oct. 22, 2008, presently pending, which was adivisional application of U.S. patent application Ser. No. 10/512,803,filed Aug. 22, 2005, which was abandoned. U.S. patent application Ser.No. 10/512,802 was a National Stage entry claiming the benefit ofInternational Application No. PCT/US2003113009, filed on Apr. 24, 2003,which claims the benefit of U.S. Provisional Application No. 60/375,944,filed Apr. 25, 2002. U.S. patent application Ser. Nos. 12/288,656;10/512,803 and 60/375,944 are incorporated herein by reference in theirentirety.

The present invention relates to surface improver compositions useful inthermosetting compositions, for instance, unsaturated polyester andvinyl ester based molding compounds. It also relates to thethermosetting compositions containing the surface improver compositions.

Several groups of compounds have been identified as improving thesurface smoothness of molded polyester and vinyl ester based reinforcedcomposites. These compounds range in composition and include epoxycompounds, polycapped oligomer adducts of long chain fatty acids withmulti hydroxyl functionality or multi epoxy functionality, and others.See Atkins U.S. Pat. No. 4,525,498. These compounds when used withthermoplastic additives, such as polyvinyl acetate based thermoplasticcompositions, improve the shrinkage control and surface smoothness ofmolded polyester and vinyl ester based reinforced composites.

Despite the improvement in surface smoothness which these compositionsimpart to molded thermosetting compositions, such as polyester and vinylester based reinforced composites, such molded composites do not presentas smooth a surface as metals. Thus, there is a need for furtherimprovement of the surface smoothness of such molded composites.

The invention is a composition comprising a blend of two or more epoxidecontaining compositions selected from epoxidized vegetable oils,epoxidized alkyl esters or cycloaliphatic epoxides. In anotherembodiment, the invention is a blend of one or more epoxidized vegetableoils, epoxidized alkyl esters, or cycloaliphatic epoxides with one ormore aromatic epoxides or epoxy functionalized polyoxyalkylene polyols.Reference to two or more epoxide compositions containing compositionsselected from epoxidized vegetable oils, epoxidized alkyl esters andcycloaliphatic epoxides means that two compositions are selected fromone, or more than one, of the listed categories. The use of the word“composition” in this context means that the selected material may be amixture of compounds, In one preferred embodiment, the epoxy compositioncomprises greater than 50 percent by weight of one or more epoxycompositions comprising epoxidized vegetable oils, epoxidized alkylesters or cycloaliphatic epoxides and 50 percent by weight or less ofaromatic epoxides or epoxy functionalized polyoxyalkylene polyols.

In another embodiment, the invention is an epoxy resin compositioncomprising two or more epoxy resin compositions selected from the groupof epoxidized vegetable oil compositions, epoxidized alkyl estercompositions, cycloaliphatic epoxide compositions, aromatic epoxidecompositions and polyoxyalkylene oxide compositions wherein thecomposition has an average oxirane number of 8.8 or less and a viscosityof 1000 (1.0 Pa.s) cps or less.

In another embodiment, the invention is a composition comprising a blendof two or more epoxide compositions wherein at least one is selectedfrom epoxidized vegetable oils, epoxidized alkyl esters, orcycloaliphatic epoxides and at least one may be selected from anaromatic epoxide or an epoxidized polyoxyalkylene polyol wherein theaverage oxirane number 8.8 or less and the viscosity is 1000 centipoise(1 Pa.s) or less.

A more preferred epoxy resin composition comprises in one partepoxidized linseed oil and/or octyl epoxytallate and a liquid epoxyresin. Preferably, the first part is present in an amount of 50 percentby weight or greater of the composition. In another embodiment the epoxycomposition comprises a blend of epoxidized linseed oil and octylepoxytallate. Preferable, the two epoxy components are present in aweight ratio of 3:1 to 1:3, and most preferably 1:1.

The epoxy compositions of the invention are useful as additives insurface improvers used in unsaturated thermosetting resin compositions,such as polyester and vinyl ester resin based compositions.

In another embodiment the invention is a novel composition useful as asurface improver for unstaturated thermosetting resin compositions whichcomposition comprises an epoxy resin composition of this invention, athermoplastic additive comprising a thermoplastic polymer, preferablyhaving a weight average molecular weight of from 10,000 to 400,000 g/gmole; and a compound capable of dissolving the thermoplastic additiveand epoxy composition. Preferably, such compound is a crosslinkingmonomer capable of copolymerizing with unsaturated thermosetting resins.

In yet another embodiment the invention is a thermosetting resincomposition comprising:

a) one or more unsaturated thermosetting resins;

b) one or more crosslinking monomers; and

c) a surface improver composition as described herein.

Preferably the surface improver composition comprises 25 parts to 45parts by weight and preferably 30 to 40 parts of 100 parts of componentsa), b) and c).

In yet another embodiment the invention comprises molded partscomprising components a), b) and c), wherein the surface of the moldedobject has improved surface smoothness as compared to molded parts whichdo not contain part c).

Blends of epoxy compounds of the invention, such as a blend ofepoxidized linseed oil and octyl epoxytallate, when used in athermosetting composite, such as polyester or vinyl ester basedreinforced composite, provide improved surface smoothness of a moldedpanel of said composition. Additionally a 50/50 blend of two epoxycompounds provide better surface smoothness than either epoxy compoundalone or other blend ratios.

The surface improver composition comprises a thermoplastic additivepresent in an amount from 12 to 35 parts by weight, preferable from 16to 30 parts by weight, and more preferably from 20 to 27 parts byweight; an epoxy composition present in an amount from 12 to 25 parts byweight, preferably from 32 to 23 parts by weight, and more preferablyfrom 10 to 16 parts by weight; a crosslinking monomer present in anamount from 40 to 87 parts by weight, preferably 47 to 81 parts byweight, and more preferably from 57 to 70 parts by weight wherein thereare 100 total parts by weight. Weights are based on the weight of thethermoplastic additive, epoxy composition, and crosslinking monomer.Preferably, the amount of each component is chosen so as to form asingle phase system.

The unsaturated thermosetting resins suitable for use in accordance withthe present invention include those unsaturated polymeric materialswhich can be crosslinked to form thermoset articles. Typically, theunsaturated thermosetting resins have an average molecular weight of atleast 500, preferably from 500 to 10,000 grams per gram mole(“g/gmole”). As used herein the term average molecular weight meansweight average molecular weight. Methods for determining weight averagemolecular weight are known to those skilled in the art. One preferredmethod for determining weight average molecular weight is gel permeationchromatography.

Typical unsaturated thermosetting resins include, for example,polyesters, vinyl esters, epoxy diacrylates, polyester diacrylates,polyurethane diacrylates, acrylate capped polyurethane polyacrylates,acrylated polyacrylates, acrylated polyethers and the like. Especiallypreferred thermosetting resins include polyesters and vinyl esters. Asused herein, the term “polyesters” includes vinyl esters. Suchunsaturated thermosetting resins are commercially available oralternatively can be readily prepared by those skilled in the art.Examples of suitable unsaturated thermosetting resins for use inaccordance with the present invention are described for example in U.S.Pat. Nos. 4,172,059 and 4,942,001, incorporated herein by reference.

One or more unsaturated thermosetting resins may be employed in themolding compositions of the present invention. The total amount ofunsaturated thermosetting resins in the molding compositions of thepresent invention. The total amount of unsaturated thermosetting resinsin the molding compositions of the present invention is typically from15 to 80 parts by weight, preferably from 20 to 60 parts by weight, andmore preferably from 25 to 50 parts by weight based on the weight of theunsaturated thermosetting resin, thermoplastic additive, epoxidecomposition and crosslinking monomer. Further details concerning theselection and amounts of unsaturated thermosetting resins are known tothose skilled in the art.

The crosslinking monomers suitable for use in accordance with thepresent invention include materials which are copolymerizable with theunsaturated thermosetting resins. The crosslinking monomer also servesthe function of dissolving the thermosetting resin thereby facilitatingits interaction with the other components of the molding composition.Preferably, the monomer contains olefinic unsaturation, more preferablyethylenic unsaturation. Typical olefinically unsaturated monomersinclude, for example, styrene, vinyl toluene isomers, methylmethacrylate, acrylonitrile and substituted styrene such as, forexample, chlorostyrene and alphamethylstyrene. Multifunctional monomers,such as, for example, divinylbenzene or multifunctional acrylates ormethacrylates may also be employed. Styrene is a preferred monomer foruse in the compositions of the present invention. One or morecrosslinking monomers may be used in the molding compositions of thepresent invention. Typically, the total amount of the crosslinkingmonomer is from 20 to 80 parts by weight, preferably from 30 to 65 partsby weight, and more preferably from 40 to 55 parts by weight based onthe weight of the unsaturated thermosetting resin, thermoplasticadditive, epoxy resin composition and crosslinking monomer. Suchmonomers are readily commercially available. Further details concerningthe selection and amounts of the crosslinking monomers are known tothose skilled in the art.

One or more thermoplastic additives may be employed in the moldingcompositions of the present invention. Typically, the total amount ofthe thermoplastic additive is from 3 to 30 parts, preferably from 5 to25 parts, and more preferably from 8 to 20 parts based on the weight ofthe unsaturated thermosetting resin, thermoplastic additive, epoxidecomposition and crosslinking monomer. Examples of the thermoplasticadditives suitable for use in accordance with the present invention aredescribed, for example, in U.S. Pat. No. 4,172,059, incorporated hereinby reference. Such thermoplastic additives are commercially available oralternatively can be prepared by those skilled in the art. Furtherdetails concerning the selection and amounts of the thermoplasticadditives are known to those skilled in the art.

The average molecular weights of the thermoplastic additives of thepresent invention are 10,000 g/gmole or greater, preferably 25,000 orgreater, more preferably from 50,000 or greater and most preferably80,000 or greater. The average molecular weights are preferable 400,000g/gmole or less, more preferably 300,000 or less, even more preferably250,000 or less and most preferably 200,000 or less. These thermoplasticadditives can be used in conjunction with lower molecular weightmaterials which can enhance their shrinkage control ability such asepoxies, lower reactivity secondary monomers and others. Examples ofsuch approaches are disclosed in U.S. Pat. Nos. 4,525,498, 4,755,557,and 4,374,215, incorporated herein by reference.

The epoxy compounds of this invention can be based on aliphatic,cycloaliphatic, or aromatic backbones. Preferred epoxy resins are liquidat room temperature. One class of preferred epoxy resins are epoxidizedvegetable oils. Vegetable oils are naturally occurring triglycerides(triesters of glycerol and mixed unsaturated fatty acids). Amongpreferred vegetable oils are linseed oil, soybean oil, safflower oil,corn oil, cottonseed oil, rapeseed oil and peanut oil. Theses oils canbe epoxidized at unsaturated sites to produce epoxidized vegetable oilsusing processes well known to those of average skill in the art. Morepreferred vegetable oils are soybean and linseed oil, with linseed oilmost preferred. Synthetic versions or refined versions of theseepoxidized vegetable oils may be used in the invention.

Epoxidized alkyl esters are epoxidized versions of natural esters offatty acids. Preferred epoxidized alkyl esters are derived from alkylesters of oleic or tall oil fatty acids or from alkyl epoxy stearates. Amore preferred class are the epoxidized tall oil fatty acids, commonlyreferred to epoxy tallates. Synthetic or refined versions of epoxidizedalkyl esters may be used in this invention.

Cycloaliphatic epoxides as used herein refer to epoxy compositionscontaining compounds having cycloaliphatic resins with an oxirane ringattached or fused to the cycloaliphatic ring. Preferably, the oxiranering is fused to the cycloaliphatic ring. A more preferredcycloaliphatic ring is an epoxy cyclohexane (epoxy cyclohexyl) which isrepresented by the formula

Preferred cycloaliphatic epoxide containing compositions containcompounds with an average of one or more, preferably on average of twoor more cycloaliphatic moieties with epoxide groups fused or attached.Among preferred cycloaliphatic epoxides are 3,4-Epoxycyclohexylmethyl3,4-epoxycyclohexane-carboxylate, available from The Dow ChemicalCompany under the trade designation ERL-4221 E; bis(3,4-epoxycyclohexylmethyl) adipate available from The Dow Chemical Company under the tradedesignation ERL-4299 and 1,2-Epoxy-4-vinylcyclohexane available from TheDow Chemical Company.

Aromatic epoxides as used herein refer to compositions containingcompounds having aromatic moieties with epoxide moieties attachedthereto. Among preferred aromatic epoxides are novolac and bisphenolbased aromatic epoxides. Representative of preferred bisphenol resinsuseful in this invention are those disclosed in U.S. Pat. No. 5,308,895at column 8, line 6 and represented by Formula 6. Relevant portions ofsuch patent are incorporated herein by reference. Preferably, thearomatic epoxide is a liquid epoxy resin. The most preferred aromaticepoxy resins are bisphenol-A and bisphenol-F based epoxy resins.

The epoxide terminated polyoxyalkylene polyols comprise compositionscontaining compounds wherein a polyoxyalkylene chain is functionalizedwith one or more epoxide moieties. The polyoxyalkylene chains arepreferably prepared from one or more epoxide moieties. Thepolyoxyalkylene chains are preferably prepared from one or more alkyleneoxides. Representative examples of polyalkylene based epoxy resins arethose described in U.S. Pat. No. 5,308,895 at column 8, line 9 andformula 9 and the description thereof following. Relevant portions ofsuch description are incorporated herein by reference. Preferably, thepolyoxyalkylene epoxide is derived from an ethylene oxide, propyleneoxide or mixture thereof.

In one embodiment, the compositions of the invention preferably comprisea mixture of two or more epoxide compositions where at least two areselected from different groups comprising epoxidized vegetable oils,epoxidized alkyl esters and cycloaliphatic epoxides. A most preferredblend is a blend of an epoxidized vegetable oil and an epoxidized alkylester. Preferably, at least one of the epoxides in the composition is anepoxidized vegetable oil. Preferably, all of the epoxides contained inthe compositions are selected from epoxidized vegetable oil, epoxidizedalkyl esters and cycloaliphatic epoxides. More preferably, the blend ofepoxides used contains an epoxidized vegetable oil and most preferablyepoxidized linseed oil.

It has been discovered that a blend of epoxides which have an oxiranenumber of 8.8 or less and a viscosity of 1000 centipoise or lessexhibits a surface waviness which is at least 10 percent lower, than ifeither or both of the epoxide compositions exhibit an oxirane number isgreater that 8.8 and viscosity which is greater than 1000 centipoise.

Preferably, the blend of epoxide compositions comprises at least 25percent by weight of at least 2 epoxide compositions, based on theweight of the epoxide compositions, and more preferably 33 percent byweight of at least two epoxide compositions, and most preferably 45percent by weight or greater least two epoxide compositions. Preferably,the epoxide composition blend contains no more than 75 percent of one ofthe epoxide compositions, based on the weight of the epoxidecompositions, and more preferably no more than 67 percent by weight ofone epoxide composition and even more preferably no more than 55 percentby weight or less. In a most preferred embodiment, the epoxide blend isa blend of 50 percent of one epoxide composition and 50 percent of asecond epoxide composition.

The preferred concentration of total epoxy compounds is 1 to 25 partsper hundred parts of the epoxy composition thermosetting resin,crosslinking monomer and thermoplastic additive, more preferred 2 to 10parts per hundred parts and even more preferred 3 parts to 8 parts perhundred parts.

Thickening agents may also be employed in the compositions of theinvention. Such materials are known in the art and include the oxidesand hydroxides of the metals of Group I, II and III of the PeriodicTable. Examples of preferred thickening agents include magnesium oxide,calcium oxide, calcium hydroxide, zinc oxide, barium oxide, magnesiumhydroxide and the like, including mixtures of the same. Thickeningagents are normally employed in proportions of from bout 0.1 to 6 weightpercent based on the weight of the thermosetting resin, crosslinkingmonomer, thermoplastic additive and epoxide composition.

Alternatively, a dual thickening system may be employed wherein, forexample, a metallic oxide or hydroxide and polyisocyanate in amounts ofpolyisocyanate sufficient to react with at least thirty percent of thehydroxyl groups but not more than one hundred and five percent of thehydroxyl groups present and an amount of metallic oxide or hydroxidesufficient to react with at least thirty percent of the carboxyl groupsbut not more than seventy-five percent of the carboxyl groups present.

The fiber reinforcements which are often employed in the moldingcompositions of the invention can be, for example, any of those known tothe art for use in molding compositions. Examples of such materials areglass fibers or fabrics, carbon fibers and fabrics, asbestos fibers orfabrics, various organic fibers and fabrics such as those made ofpolypropylene, acrylonitrile/vinyl chloride copolymer, and others knownto the art. These reinforcing materials are typically employed in themolding compositions at a level of from 5 to 80 weight parts, based onthe total weight of the composition and preferably 15 to 50 weightparts.

In addition to the above-described ingredients, the molding compositionsof the present invention also frequently contain pigment. The amount ofpigment may vary widely, depending on the particular molding compositionand pigment used. The pigment is typically employed in the range of 0.5to 15 weight parts based on the total weight of the composition.

The molding compositions of the invention may also contain one or moreother conventional additives, which are employed for their knownpurposes in the amounts known to those skilled in the art. Therefollowing are illustrative of such additives:

-   -   1. Polymerization initiators such as t-butyl hydroperoxide,        t-butyl perbenzoate, benzoyl peroxide, t-butyl peroctoate,        cumene hydroperoxide, methyl ethyl ketone peroxide, peroxy        ketals, and others known to the art, to catalyze the reaction        between the olefinically unsaturated monomer and the        thermosetting resin. The polymerization initiator is employed in        a catalytically effective amount, such as from 0.3 to 3 parts,        based on the weight of the unsaturated thermosetting resin,        thermoplastic additive, and crosslinking monomer.    -   2. Fillers such as clay, alumina trihydrate, silica, calcium        carbonate, and others known to the art;    -   3. Mold release agents or lubricants, such as zinc stearate,        calcium stearate, and others known to the art, and    -   4. Water.

One especially preferred molding composition in accordance with thepresent invention comprises:

-   -   (i) from 20 to 60, preferably 27 to 35 weight parts based on the        weight of the unsaturated thermosetting resin, thermoplastic        additive, and crosslinking monomer of an unsaturated polyester        and epoxide compositions;    -   (ii) from 30 to 65, preferably 47 to 55, weight parts based on        the weight of the unsaturated thermosetting resin, thermoplastic        additive, epoxide composition and crosslinking monomer of an        olefinically unsaturated monomer which is copolymerizable with        the unsaturated polyester;    -   (iii) from 5 to 25, preferably 10 to 14, weight parts based on        the weight of the unsaturated thermosetting resin, thermoplastic        additive, epoxy composition and crosslinking monomer of a        polyvinyl acetate homopolymer or copolymer having a weight        average molecular weight of from 70,000 or greater, more        preferably 80,000 g/gmole or greater and preferably 250,000 or        less and more preferably 200,000 grams per gram mole or less        and;    -   (iv) from 2 to 10, preferably 3 to 8, weight parts based on the        weight of the unsaturated thermosetting resin, thermoplastic        additive, epoxy composition and crosslinking monomer.

The molding compositions of the present invention can be prepared bymethods known to those skilled in the art, such as for example, mixingthe components in a suitable apparatus such as Hobart mixer attemperatures on the order of 20° C. to 50° C. The components may becombined in any convenient order. Generally, it is preferable that thethermosetting resin and thermoplastic additive are added in liquid formby preparing a solution thereof in the crosslinking monomer. All theliquid components are then typically mixed together before adding thefillers, thickening agents and optional ingredients.

Once formulated, the molding compositions can be molded into thermosetarticles of the desired shape, for example, automotive fenders, hoods,bathtubs, doors, and the like. The specific conditions used in themolding process depend on the composition being molded as well as uponthe nature of the particular articles desired, the details of which areknown to those skilled in the art.

The molding compositions are suitable for use, for example, as sheetmolding compounds and bulk molding compounds, with sheet moldingcompounds being more typical. For example, sheet molding compound can beproduced by laying down a first layer of the molding composition, thatis, paste, on a first layer of polyethylene film or the equivalentthereof, laying on this first layer of the paste filler reinforcementssuch as chopped glass fibers, and laying thereover a second layer of thepaste. The two layers of the paste with the filler reinforcementssandwiched therebetween are then topped with a second sheet ofpolyethylene film and the resulting composite (sheet molding compound)is stored. Further details concerning the manufacture, handling and useof sheet molding compounds and bulk molding compounds are known to thoseskilled in the art.

The following examples are provided for illustrative purposes and arenot intended to limit the scope of the claims which follow. All partsand percentages are by weight unless otherwise specified.

The following materials and terms were used in the examples set forthbelow:

GLOSSARY

S342 is a highly reactive unsaturated polyester resin sold by AlphaOwens Corning and is used for automotive SMC applications.BMC stands for bulk molding composition.CM-2015 is a 35 percent carbon black pigment dispersion available fromPlasticolors, Inc., Ashtabula, Ohio.Modifier E is a 5 percent solution of parabenzoquinone indiallylphthalate.Luperox P is a 98 percent, solution of t-butylperoxy benzoate sold byElf Atochem North America, Philadelphia Pa.VR-3 is a viscosity reducer for SMC/BMC sold by The Dow ChemicalCompany, Mildland, Mich.Maglite D is a technical grade magnesium oxide sold by marine MagnesiumCompany.LPA refers to low profile additive.Neulon G is a proprietary carboxylated poly(vinyl acetate) manufacturedand sold by The Dow Chemical Company, Midland, Mich.LP-90 is a 40 percent solution of poly(vinyl acetate) homopolymerdissolved in styrene and sold by The Dow Chemical Company, Midland,Mich.Hubercarb W4 is a calcium carbonate of 5 micron particle size sold byJ.M Huber Company.SMC stands for sheet molding compound.SWI stands for surface waviness index as measured by a Diffracto D-sightaudit station produced and sold by Diffracto Ltd.UPE stands for unsaturated polyester.ON stands for oxirane number.A-Paste is the portion of the formulation containing either some or allof the thermosetting resin, the crosslinking monomer, the thermoplasticadditive, the polymerization initiators, the mold release agents, thepigments, the filler, etc.B-Paste is the portion of the formulation containing either some or allof the vehicle, the pigment, the crosslinking monomer, the thickeners,the filler, etc.PPG 5509 is a fiber glass reinforcement sold by PPG Industries.

Procedure for Preparation of Sheet Molding Compound (SMC) Formulations

All the liquid components were weighed individually into a five gallonopen top container placed on a Mettler balance. The contents of thecontainer were then mixed with a high speed Cowles type dissolver. Theagitator was started a slow speed, then increased to medium speed tocompletely mix the liquids over a period of 2-3 minutes. The moldrelease agent was next added to the liquids and mixed until completelydispersed. The filler was next added gradually until a consistent pastewas obtained and the contents were then further mixed to a minimumtemperature of 90° F. (32° C.). The thickening agent was next mixed intothe paste over a period of 2-3 minutes. The paste was next added todoctor boxes on a sheet molding compound (SMC) machine where the pasteis metered into a film on the carrier sheet where it is further combinedwith fiber glass (1 inch (2.54 cm) fibers). The sheet molding compoundwas then allowed to mature to molding viscosity.

Preparation of Molding Test Panels

Flat panels for surface evaluation were molded on a 200 ton (8181 metricton) Lawton press containing a matched die set of 18″ by 18″ (47×47 cm)chrome plated molds. The female cavity is installed in the bottom andthe male portion is at the top. Both molds are hot oil heated and arecontrolled so that they can be operated at different temperatures. Forthe present molding, the top and bottom temperatures were 295° F. to305° F. (146 to 151° C.). 1200 g samples of molding compound wereemployed, and the molded part thickness was 2.120″ (0.30 cm). Themolding pressure, which can be varied from 0 to 1000 psi (0 to 6895kPa), was run at maximum pressure. The panels were laid on a flatsurface, weighed to keep them flat, and allowed to cool overnight.

Procedure for Determining Surface Smoothness of Molded Panels

Surface quality measurements were performed on a Diffracto D-sight AuditStation-2 manufactured and sold by the Diffracto Co., Ltd. The surfacewaviness index (SWI) provided by this instrument is the standarddeviation of the panel's surface with regard to long term waviness, ascompared to the surface of a perfectly flat panel, whose long termwaviness is zero. The smaller the SWI number, the smoother the panel.

EXAMPLE 1

Table 1 showed SMC formulations utilizing expoxidized linseed oil, octylepoxytallate, and blends of the same. In Table 1 all number were partsby weight. In preparing the SMC, 72 percent of the composition describedwas blended with 28 percent by weight of PPG 5509 glass fibers. The Bside comprised LP-90, 29.90 percent; Styrene, 12.80 percent; Maglite D,9.90 percent, CM-2015, 0.50 percent and Hubercarb W4, 46.90 percent.Table 2 showed the surface waviness index of the molded panels asdetermined on the Diffracto D-sight audit station. The 50/50 blend ofthe epoxy compounds gave a smother surface (lower surface wavinessindex) than either epoxy compound alone at other blend ratios.

TABLE 1 SMC Formulations Utilizing Epoxy Compounds 1 2 3 4 5 S342 55 5555 55 55 Neulon-G 35 35 35 35 35 Styrene 10 10 10 10 10 Epoxidizedlinseed oil 0 1.5 3 4.5 6 Octyl epoxytallate 6 4.5 3 1.5 0 Modifier E0.4 0.4 0.4 0.4 0.4 Luperox P 1.8 1.8 1.8 1.8 1.8 Zinc Stearate 2.5 2.52.5 2.5 2.5 VR3 2 2 2 2 2 Hubercarb W4 215 215 215 215 215 B-Side 7.37.3 7.3 7.3 7.3 LP-90 29.9 percent Styrene 12.8 percent Maglite D  9.9percent CM-2015  0.5 percent Hubercard W4 46.9 percent PPG 5509   28percent 28 percent 28 percent 28 percent 28 percent

TABLE 2 Surface Waviness Index of Formulation in Table 1 EpoxidizedOctyl Waviness Linseed oil, pts epoxytallate, pts Index 0 6 272 1.5 4.5222 3 3 184 4.5 1.5 213 6 0 273

Several samples were prepared and tested for surface waviness asdescribed hereinbefore. The oxirane number was determined on each sampleaccording to the procedure described in ASTM D1652 Standard Test Methodsfor Epoxy Content of Epoxy Resins, Test Method B. The viscosity wasdetermined using a Brookfield viscometer at ambient temperature. Theresults were complied in Table 3.

TABLE 3 Visc. Epoxide SWI (cps) (Pa · s) ON Octyl Epoxy Tallate¹ 272 270.027 4.6 Octyl Epoxy Ester² 214 32.5 (0.0325) 5.77 Octyl EpoxyTallate¹/Bisphenol 222 160 (0.160) 6.3 based Epoxy resin 1³ Octyl EpoxyTallate¹/Bisphenol 227 100 (0.100) 6.65 based Expoxy resin 2⁴ EpoxidizedLinseed Oil⁵/Octyl 184 128 (0.128) 7.1 Epoxy Tallate¹ Epoxidized LinseedOil⁵/Octyl 160 85 (0.085) 7.71 Epoxy Ester² Octyl Epoxy Tallate¹/ 208 70(0.070) 8.1 Cycloaliphatic Epoxide⁶ Bisphenol based epoxy resin 1³ 27516100 16.100 8.2 Bisphenol based epoxy resin 3⁷ 231 13700 13.700 8.4Bisphenol based epoxy resin 224 11700 11.700 8.7 1³/Bisphenol basedepoxy resin 4⁸ Bisphenol based epoxy resin 347 8500 8.500 8.91³/Bisphenol based epoxy resin 2⁴ Bisphenol based epoxy resin 2⁴ 2416800 6.800 9 Bisphenol based epoxy resin 4⁸ 199 11500 11.500 9Epoxidized Linseed Oil⁵/Bisphenol 209 1430 1.430 9.33 based epoxy resin1³ Bisphenol based epoxy resin 2⁴ 232 1210 1.210 9.35 Epoxidized LinseedOil⁵ 273 682 .682 9.648 Epoxidized Linseed Oil⁵/ 196 502 .502 10.6Cycloaliphatic Epoxide⁶ Cycloalihatic epoxide⁶ 263 337 .337 11.6¹Available from Witco under the trademark DRAPEX 4.4. ²Available fromAtofina under the trademark VIKOFLEX 4050. ³Available form The DowChemical Company under the Trademark and designation DER 331 and was astandard, nondiluted, low molecular weight liquid epoxy resin having anEEW of 182-192. ⁴Available form The Dow Chemical Company under theTrademark and designation DER 332 and was a low epoxide equivalentweight, high purity diglycidyl ether of bisphenol-A. Low viscosity andcolor having an EEW of 171-175. ⁵Available from The Dow Chemical Companyunder the trademark FLEXOL LOE. ⁶3,4-epoxycyclohexylmethyl3,4-epoxycylohexane-carboxylate available form The Dow Chemical companyunder the Trademark and designation ERL-4221. ⁷Available form The DowChemical Company under the Trademark and designation DER 383 which islow viscosity liquid epoxy resin having an EEW of 1176-183. ⁸Availableform The Dow Chemical Company under the Trademark and designation DER330, which is low viscosity, undiluted, low epoxide equivalent weightliquid epoxy resin having an EEW of 176-185. EEW means epoxy equivalentweight.

Table 3 illustrated that compositions containing blends of epoxidizedvegetable oils, epoxy alkyl esters and cycloaliphatic epoxides with oneanother and with aromatic epoxides demonstrated lower surface wavinessindices than compositions containing an individual class of epoxides.Data from Table 3 was represented below to better illustrate this.

SWI Octyl Epoxy Ester 214 Blend 160 Epoxidized LO 273 Bisphenol-AEpoxyl³ 275 Blend 209 Epoxidized LO 273 Bisphenol-A Epoxy2⁴ 241 Blend232 Epoxidized LO 273 Octyl Epoxy Tallate 272 Blend 184 Epoxidized LO273 Bisphenol-A Epoxy 1³ 275 Blend 222 Octyl Epoxy Tallate 272Bisphenol-A Epoxy 2⁴ 274 Blend 227 Octyl Epoxy Tallate 272 Bisphenol-AEpoxy 1³ 241 Blend 347 Bisphenol-A Epoxy 2⁴ 275 Epoxidized linseed oil273 Blend 196 Cycloaliphatic epoxide 263 Octyl epoxy tallate 272 Blend208 Cycloaliphatic 263

The data in Table 3 was statistically analyzed to examine twoparameters, first epoxide oxirane number greater that 8.8 and less than8.8 and second viscosity less than 1000 (1.0 Pa.s) and greater than 1000cps (1.0 Pa.s). The average surface waviness index of formulationscontaining epoxides and epoxide blends meeting these criteria weresegregated into four groups based on these criteria and averaged. Theresults were shown below.

Average Surface Waviness (SWI) Epoxide(s) Greater than 245 246 Oxirane8.8 Number Less than 213 243 8.8 Less Than Greater Than 1000 1000 (1.0Pa · s) (1.0 Pa · s) Epoxide(s) Viscosity, cps

These data demonstrated that a blend of epoxides having an oxiranenumber of 8.8 or less and a viscosity of 1000 cps (1.0 Pa.s) or lessgave the best surface waviness index numbers.

1. A surface improver composition for thermosetting resin compositions,the surface improver composition comprising an epoxy resin compositionhaving a blend of epoxidized linseed oil and octyl epoxytallate, athermoplastic additive comprising a thermoplastic polymer, and acompound capable of dissolving the thermoplastic additive and epoxycomposition.
 2. The surface improver composition of claim 1 wherein thecompound capable of dissolving the thermoplastic resin and epoxycomposition is a crosslinking monomer capable of copolymerizing withunsaturated thermosetting resins.
 3. The surface improver composition ofclaim 2 wherein the thermoplastic additive is present in an amount of 12to 35 parts by weight, the epoxy composition is present in an amount of1 part to 25 parts by weight and the crosslinking monomer is present inan amount of 40 parts to 87 parts by weight wherein there are a total of100 parts by weight.
 4. The surface improver composition of claim 1comprising from 25 percent to 75 percent of the epoxidized linseed oilby weight based on the total weight of the epoxidized linseed oil andthe octyl epoxytallate and 25 percent to 75 percent by weight of theoctyl epoxytallate based on the total weight of the epoxidized linseedoil and the octyl epoxytallate.
 5. The surface improver composition ofclaim 4 wherein the epoxy resin composition comprises 50 percent of theepoxidized linseed oil by weight based on the total weight of theepoxidized linseed oil and the octyl epoxytallate and 50 percent byweight of the octyl epoxytallate based on the total weight of theepoxidized linseed oil and the octyl epoxytallate.
 6. The surfaceimprover composition of claim 1 having an oxirane number of 8.8 or lessand a viscosity of 1000 cps (1.0 Pas) or less.
 7. A thermosetting resincomposition comprising: a) one or more unsaturated thermosetting resins;b) one or more crosslinking monomers; and c) a surface improvercomposition according to claim
 1. 8. The composition of claim 7 whereinthe surface improver composition comprises 25 to 45 parts of 100 partsof components a), b) and c).
 9. Molded parts comprising the compositionof claim 7 wherein the surface of the molded object has improved surfacesmoothness as compared to molded parts which do not contain part c).